Field
The described technology generally relates to a thin film deposition device and method of depositing thin film materials.
Description of the Related Technology
A thin film manufacturing process, such as a thin film encapsulation of an organic light emitting device, generally uses a deposition process that generates steam from a deposition source for adsorption of the steam to the substrate surface.
Recently, atomic layer deposition (ALD), which can more uniformly and precisely form a thin film, has become the preferred deposition process for many applications. In ALD, a precursor is first adsorbed to the surface of a substrate and then a reactant is supplied and an atomic layer is formed from the chemical reaction between the precursor and the reactant.
Among generally used atomic layer deposition processes, one of these is a traveling wave-type atomic layer deposition process. Here, a substrate and a deposition mask are aligned in an atomic layer deposition chamber, steam from a deposition source is injected into the chamber, and the steam is controlled to be adsorbed to the surface of the substrate while being moved through an outlet. However, in this process, a large mother substrate is generally used to improve productivity, and thus when steam is injected into a large-sized deposition chamber (sufficiently large to have the mother substrate), flow of the injected steam cannot be controlled. As a result, uniformity of the atomic layer deposited to the substrate may be degraded.
When ALD process time is extended so as to reduce the incidence of non-uniformities, a tact time (i.e., maximum process time) is inevitably extended, thereby reducing productivity. Further, steam flows through a gap between the deposition mask and the substrate, thereby causing deposition failure.
When a spatial-type ALD process is used, developed to improve deposition speed, different steam nozzles are alternately arranged above the substrate and deposition can be promptly performed while the substrate slides below the nozzle. However, a vapor cross current can occur between adjacent gas nozzles, and thus, foreign particles may lodge on the substrate, thereby causing deposition failure.
The above information disclosed in this Background section is only to enhance the understanding of the background of the invention, and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.